Soldering copper pipes with their own hands

Copper pipes are often installed today in the heating networks, as well as in the highways of water and gas supply of residential buildings. In addition, these products are widely used in air conditioning systems and freezing devices of various types.

To obtain a permanent pipe joint, special soldering techniques have been developed, which are realized by introducing a special molten material (solder) into the contact zone. In this case, the required quality of connection is achieved only in the case when the melting point of the solder is below the melting point of the pipe elements being joined.

Immediately, we note that soldering copper pipes with your own hands will require you to be particularly careful and have some preparation.

Advantages of brazed copper structures

The growing popularity of systems assembled on the basis of copper pipes is easily explained by the presence of such attractive qualities in the latter as:

• reliability, durability and strength;
• ease of processing the source material;
• ability to function at high pressures and temperatures.

In addition, due to the use of such technologies, it is possible to save on component materials (fittings, adapters, etc.), which significantly reduces the total cost of the work performed.

Soldering methods and tools

Copper pipes can be brazed in one of the following temperature conditions:

1. High-temperature brazing (melt temperature of about 600-900 degrees) is used for pipelines operating under high loads.
2. Low-temperature mode, usually practiced in everyday life (temperature in the soldering zone up to 450 degrees).

To obtain a reliable joint of the pipes during the soldering process, the following tool must be used:

1. Pipe cutter, with which you can get a smooth cut (perpendicular to the axis of the pipe billet).
2. Special fixture used for chamfering and deburring.
3. A pipe expander that allows to prepare the joint for soldering (the depth to which the pipe is processed with its help must be equal to the diameter of the workpiece).
4. Gas acetylene-oxygen torch used for soldering copper pipes.

The depth at which the pipe is machined with an expander should be equal to the diameter of the workpiece.

In addition, for working with low-melting solder, a special thermal dryer can be used to heat the welding point to the desired temperature.

The use of a heat gun allows you to easily adjust the temperature in the weld zone, as well as to maintain the desired temperature. With the help of the replaceable nozzles supplied with the device, you will be able to direct a stream of heated air to the desired point.

Materials used in soldering

Before soldering copper pipes, you should be familiar with the materials that act as solders, which, depending on their refractoriness, are divided into hard and soft.

Soda

Solders of increased refractoriness are made, as a rule, in the form of rods of a certain profile. The use of solders of this type is possible when heating the soldering zone to 900 degrees, which allows to obtain a very reliable connection. Solders of this class are often used in the installation of water and gas supply lines, as well as in the repair of freezing equipment and air conditioning systems.

The most famous representatives of such solders are copper-phosphorus self-fluxing mixtures with various additives (Cu94 P6 and Cu92 P6 Ag2). Small additives (about 6%) of phosphorus or silver can reduce the melting point of the solder to 750 degrees. The expansion coefficient of such a material coincides with the same indicator for copper, which contributes to the formation of a strong and reliable connection.

The so-called "soft" solders are made in the form of ordinary thin wire and are used for low-temperature soldering of copper pipes, produced at home. These solders are made, as a rule, on the basis of such known materials as tin, lead (or their alloys).

Fluxes

To facilitate the soldering of copper pipes, special liquid or paste-like compositions (fluxes) are used, the correct choice of which determines the success of the event as a whole.

These compounds are also divided into low-temperature (up to 450 degrees) and high-temperature, used at temperatures above 450 degrees.

They contribute to:

• cleaning the soldering point from oxides;
• its protection from oxygen in ambient air;
• creating conditions for smooth spreading of the soldering composition;
• improve the adhesion of the metal to the solder.

During soldering work, it is necessary to carefully ensure that the solder heated to the desired temperature evenly spreads over the surfaces of the jointed workpieces, thus forming a reliable joint. After the final cooling of the site of soldering, remove all excess flux from it.